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Insomnia (Sleepless Nights)

What Is Insomnia?

Last modified: 
16/04/2013 - 13:47

Contributing Author: Guy Slowik FRCS

Insomnia is a sleep disorder in which a person experiences poor sleep or has trouble sleeping. Insomnia can involve:

  • Difficulty falling asleep
  • Difficulty staying asleep (that is, waking up many times during the night), without necessarily having had any difficulty falling asleep
  • Waking up too early in the morning
  • Not feeling refreshed after a night's sleep

In any of these cases the person feels tired the next day, or feels as if he or she did not have enough sleep.

Poor sleep for any length of time can lead to mood disturbances, lack of motivation, decreased attention span, trouble with concentration, low levels of energy, and increased fatigue.

About one-third of the average person's life is spent sleeping. Healthy sleep is vital to the human body and important for the optimal functioning of the brain and other organs.

There are three types of insomnia:

  • Transient, or mild, insomnia - sleep difficulties that last for a few days; there is little or no evidence of impairment of functioning during the day
  • Short-term, or moderate, insomnia - sleep difficulties that last for less than a month, that mildly affect functioning during the day, together with feelings of irritability and fatigue
  • Chronic, or severe, insomnia - sleep difficulties that last for more than a month, that severely impair functioning during the day, and cause strong feelings of restlessness, irritability, anxiety, and fatigue

Need To Know:

Q: What is the right amount of sleep I should get?

A: Since everyone has different sleep needs, there is no "correct" amount of sleep. On average, most people need between seven and nine hours of good quality sleep each night in order to feel alert the next day. But some function perfectly well with only four or five hours a night. The key to healthy sleeping seems to be a consistent pattern, rather than the number of hours one sleeps.

Is Insomnia Serious?

Insomnia can have physical and psychological effects. The consequences of insomnia include:

  • Impaired mental functioning. Insomnia can affect concentration and memory, and can affect one's ability to perform daily tasks.
  • Accidents. Insomnia endangers public safety by contributing to traffic and industrial accidents. Various studies have shown that fatigue plays a major role in automobile and machinery accidents. As many as 100,000 automobile accidents, accounting for 1,500 deaths, are caused by sleepiness.
  • Stress and depression. Insomnia increases the activity of the hormones and pathways in the brain that cause stress, and changes in sleeping patterns have been shown to have significant affects on mood. Ongoing insomnia may be a sign of anxiety and depression.
  • Heart disease. One study reported that people with chronic insomnia had signs of heart and nervous system activity that might put them at risk for heart disease.
  • Headaches. Headaches that occur during the night or early in the morning may be related to a sleep disorder.
  • Economic effects. Insomnia costs the U.S. an estimated $100 billion each year in medical costs and decreased productivity.

Normal Sleep

Sleep is not a simple process. Many different parts of the brain control and influence sleep at different stages. There are two natural daily peak times for sleeping: at night and at mid-day, which in parts of the world is traditional "siesta" time.

Here is how the body initiates sleep:

  • As light fades, cells in the retina of the eye send a signal to a cluster of nerve cells located in the hypothalamus, in the center of the brain.
  • These cells in turn send a message to the pineal gland in the brain to produce the hormone melatonin, which causes a drop in body temperature and sleepiness.
  • At the same time, another cluster of nerve cells in the brain is believed to deactivate three major chemical messengers in the body, that keep us alert: histamine, norephinephrine, and serotonin.

There are two distinct phases of sleep:

  • Non-rapid eye movement (Non REM) sleep - The quiet or restful phase of sleep, also referred to as "slow wave sleep"; it is divided into four stages of progressively deepening sleep
  • Rapid eye movement (REM) sleep - The phase of sleep in which the brain is active and dreaming occurs; it is also known as "dream sleep"

When we first go to sleep, the "brain waves" (the electrical activity normally produced in the brain) slow from a frequency of 10 cycles per second that usually occurs while we're awake, to about 6 cycles per second as our alertness decreases and we fall asleep. Then after about an hour, there is a sudden increase in brain wave activity for a few minutes when the electrical activity in the brain speeds up, similar to normal waking. This is REM sleep. During this time if the person is woken up, he will say he was dreaming.

Then the electrical activity of the brain slows down again. This cycle may be repeated several times during one night's sleep. Total REM sleep for the night is about 20% of the total sleep time. So we spend about a fifth of our sleeping time dreaming.

The phases of sleep occur in a repeated cycle of Non REM followed by REM sleep, with each cycle lasting about 90 minutes. The sleep cycle is repeated four to six times a night. It is possible to identify which stage of sleep a person is in by measuring different activities of the brain and body.

Each phase of sleep is important. Research suggests that Non REM sleep may play a role in bolstering the immune system and may also be tied to the rhythms of the digestive system. Experts believe that REM sleep is necessary for long-term emotional well-being and may help bolster memory.

Need To Know:

If your insomnia lasts longer than a few weeks and is affecting your mood, relationships, and ability to function well, it is a good idea to see a doctor, therapist, or sleep specialist.

What Are Sleep Disorders?

An estimated 40 million Americans experience some type of sleep disorder, but 95 percent of them go undiagnosed and untreated, simply because they do not realize they have a problem or because they think that nothing can be done for them.

Common sleep disorders include:

  • Insomnia, an inability to sleep or to remain asleep throughout the night
  • Obstructive sleep apnea, in which a person's breathing passages become temporarily blocked during the night; this condition is often marked by excessive snoring
  • Chronic sleep apnea, a neurological condition in which the brain "forgets" to instruct the body to breathe
  • Restless leg syndrome, in which a person has occasional movement and/or uncomfortable sensations in his or her legs, feet, or toes just before they fall asleep
  • Hypersomnia, an increase in sleep by about one-fourth of a person's regular sleep patterns
  • Narcolepsy, in which a person gets sudden attacks throughout the day and night of drowsiness and sleep that cannot be controlled
  • Parasomnias, which are vivid dreams and physical activities that occur during sleep, such as sleepwalking (somnambulism) and episodes of screaming and flailing about (night terrors).

Nice To Know:

Chronic sleep deprivation - in which a person sleeps soundly, but just doesn't get enough sleep - is not classified as a sleep disorder, but it contributes greatly to our sleepy society. Experts say most of us need at least one more hour of sleep per night than we get.

Facts about insomnia:

  • Studies estimate that about one-third of the adult population in the world experiences some insomnia each year.
  • Experts estimate that only about 5 percent of people with insomnia seek medical help, and 69 percent never even mention the problem to their doctor.
  • More than 35 million Americans suffer from long-lasting insomnia, with 20 to 30 million others experiencing shorter-term sleeplessness.
  • Insomnia costs the U.S. approximately $100 billion each year in medical costs and decreased productivity.
  • In the U.S., as many as 100,000 automobile accidents and 1,500 deaths from these accidents are caused by sleepiness.
  • In one study, 40 percent of people with insomnia also had a psychiatric disorder.
  • At least 70 percent of people with depression also experience insomnia.
  • As many as 25 percent of people with anxiety disorders also experience insomnia.
  • Substance abuse - especially alcohol, cocaine, and sedatives - plays a role in an estimated 10 to 15 percent of cases of chronic insomnia.
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From Andrew Maynard - Chair of the University of Michigan Department of Environmental Health Sciences, with help from David Faulkner - 2013 Master of Public Health graduate.